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Ethernet working (show of hands, please)?
Ivo Noorhoff.
32
replies
We used the Sparkfun Magjack breakout board here in a class and twenty students all got it working on ten different computer setups. Only pain was soldering the magjack connector and header pins to the breakout board. Each magjack company has different pinouts so watch out for that! Four wire setup below is based on the magjacks they shipped us from Sparkfun a few weeks ago:
|
mbed |
adapter |
|
TD+ |
P1 |
|
TD- |
P2 |
|
RD+ |
P7 |
|
RD- |
P8 |
P.S. The biggest problem was getting the computer support people to enable DHCP support on our network for the new boards. Had to get them all of the NIC address info and wait awhile. Try this code first just to see any packets out there
Let me start by apologizing for quoting the full message. It is too relevant.
Harry Weston wrote:
Can anybody please help me. I find the details of the Ethernet set up very confusing, so I too am having trouble getting my link to mbed to work. I have the mbed plugged into a 'Cool Components Workshop Board (version 2)', plugged into my PC (XP SP3) via a 'crossover' cable. I did no better with a 'straight' cable either. I have tried several of the test programs, with no success.
Windows report on this link is:
Local Area Connection 3 This connection has limited or no connectivity. You might not be able to access the Internet or some network resources. This problem occurred because the network did not assign a network address to the computer.
Details:
Property Value Physical Address: D8-5D-4C-81-F5-A2 IP Address: 169.254.112.239 Subnet Mask: 255.255.0.0 Default Gateway: DNS Server: WINS Server:
Attempting to find a solution on the Internet I came across this, which looks pretty relevant:
Quote:
Bottom line: if you're getting a 169.254.x.x IP address then something about your network setup isn't working, and you probably want to investigate what and why.
This is normal: your laptop normally receives its ip-address from a dhcp server. when connected to the MBED there is none, so it configures only the autoconf (169.254) address.
Harry Weston wrote:
Using this program (I have removed blank lines to save space):
#include "mbed.h"
#include "EthernetNetIf.h"
#include "HTTPClient.h"
EthernetNetIf eth; // Original from mbed site
/* EthernetNetIf eth( // alternative I tried -- no success
IpAddr(192,168,0,120), //IP Address
IpAddr(255,255,255,0), //Network Mask
IpAddr(192,168,1,254) , //Gateway
IpAddr(192,168,1,254) //DNS
); */
HTTPClient http;
int main() {
printf("Setting up...\n\r");
EthernetErr ethErr = eth.setup();
if(ethErr)
{
printf("Error %d in setup.\n\r", ethErr);
return -1;
}
printf("Setup OK\n\r");
HTTPText txt;
HTTPResult r = http.get("http://mbed.org/media/uploads/donatien/hello.txt", &txt);
if(r==HTTP_OK)
{
printf("Result :\"%s\"\n\r", txt.gets());
}
else
{
printf("Error %d\n", r);
}
while(1)
{
}
return 0;
}
Using the program as above I get the following where I have left justified the lines as there is no 'carriage return' in the output and it wraps round at the right margin:
Tera Term output:
Setting up... [..\fwk\if\eth\EthernetNetIf.cpp:setup@86] HW Addr is : 00:02:f7:f0:40:e5. [..\fwk\if\eth\EthernetNetIf.cpp:setup@99] DHCP Started, waiting for IP... [..\fwk\if\eth\EthernetNetIf.cpp:setup@131] Timeout. Error -65534 in setup.
(no lights on RJ45 socket, LEDs flashing alternately 1&4 and 2&3
If I comment out the first " EthernetNetIf eth;" line and 'uncomment' the next and the table, I get:
Tera Term output:
Setting up... [..\fwk\if\eth\EthernetNetIf.cpp:setup@86] HW Addr is : 00:02:f7:f0:40:e5. [..\fwk\if\eth\EthernetNetIf.cpp:setup@142] Connected, IP : 192.168.0.120 Setup OK Error 3
(No lights on RJ45 socket, nor leds on mbed )
Both quite normal. In the first case you again have no dhcp server, so the MBED does not get an ip-address. That is what the error -65534 indicates. Try connecting your MBED to your normal internet link (assuming your modem does dhcp), and it will get an address AND it can access the page it tries to fetch from the MBED website.
And about the leds: that is normal: the stack probably does not support the leds (I did not check though). My leds (on the same baseboard) do not turn on either. There is no way to specify the pin numbers.... Oh, and by the way: for me the http client works great.
All -
Everything else on mBed has been stupidly simple to get working, but I'm ready to claim that ethernet does not. A handful of folks claim that they have it working. Who else is having problems with ethernet?
I have tried for almost two weeks to get ethernet working on several mBeds. So far I have tried wiring directly, wiring through capacitors, liberating a transformer and RJ45 jack and wiring through those, and finally the "recycle a board" method. Unfortunately, still no joy on ethernet. I'm watching the signals on an oscilloscope, and everything looks good enough for ethernet. I have tried three mBeds (V5.1), two hubs, four ethernet cables (one of them a crossover), and the programs "ethspam", "ethsniff", "EthernetTester", "EthernetTesterGood", "UDPTest", "NetTool", "NetServices", and many of my own renditions of bashing those programs together.
I have read datasheets and application notes for all the parts, plus a few ethernet primers. Several folks on the forum apparently cross the + and - signals. Just to be sure, I am pretty sure that I tried every combination of R+/R- T+/T- that makes any sense at all. I get bits on the oscilloscope, but no DHCP, no packets seen with WireShark, no HTTP server, no HTTP get, no UDP, no NTP, no ARP, no nothing.
As an aside, I'm pretty sure (after working with "ethspam" for a few days) that the mBed compiler has a bug. It does not consistently use the correct number of bytes in the ethpkt structure (clobbering one of the bytes of the six character address arrays). Removing the "__packed" directive simply moves the problem, but does not correct it. Clearly, this could affect a lot of things, so I'm wondering if anybody else has noticed it.
I'll keep plugging away at it, but I'd like to know who else tried but has no ethernet?
Regards,
- Gary